The present invention pertains to devices for resharpening the dulled blades of handheld scissors and more particularly the corrugated blades of same.
Handheld corrugated scissors are used in many applications where the material is so slippery that it tends to slide along the edge of the blades when being cut by the scissors. The corrugations tend to prevent the material from sliding along the edge of the blade as the scissor is being used to cut the slippery material. For many applications, handheld scissors provide the most efficient and effective means of cutting materials. Many of these materials used in these applications are difficult to cut and tend to dull the blades of the scissors that are used to perform the cutting. Thus, to avoid discarding scissors with dull blades, a need exists for a device that resharpens the blades of the scissors. One example of such a device is disclosed in commonly owned U.S. Pat. No. 4,528,778 to Wolff, which is hereby incorporated herein in its entirety by this reference.
If the blade that needs resharpening has a corrugated blade surface, once the blade surface has been resharpened with a honing device, the resharpened edge loses the corrugations. In order to cut new corrugations into the resharpened edge, a file must be used by hand. This process of hand filing in order to provide the corrugations to the resharpened edge of the scissor's blade is tedious and time consuming and requires a certain amount of skill that must be learned by the filer.
Machines for manufacturing the corrugated blades of handheld scissors are known. At least one such serration and profile grinding machine is available from American Siepmann Corporation, 65 Pixley Industrial, Rochester, N.Y. Machines of this type typically employ a rotary grinding wheel that extends axially for substantially the entire length of the blade that is to be corrugated. Some such machines mill a sharp edge on the blade surface and simultaneously gouge out portions of the sharpened surface to form the corrugations along the blade edge. The corrugations in the grinding wheel are disposed in planes parallel to each other and normal to planes that contain the axis of rotation of the grinding wheel. In other machines the corrugations in the grinding wheel are disposed in planes parallel to each other and at an angle with respect to planes that contain the axis of rotation of the grinding wheel. However, the grinding wheels of such machines are expensive, and are prone to being damaged during use as well as prone to damaging the blade that is to be corrugated. Moreover, in some instances different wheels of different axial lengths must be mounted and dismounted to accommodate sharpening and corrugating blades of different lengths.